Five people on Friday were held for questioning by the Kochi police after an e-mail was sent from Kochi, threatening to assassinate President Pratibha Patil and Congress chief Sonia Gandhi on or before Nov 14.
Kochi police commissioner Manoj Abraham told IANS that the e-mail was sent from a cyber cafe in Kochi at 2.30 pm Oct 24.
"Right now no arrests have been made and five people, including an engineering student, who were using the internet cafe at that time are being questioned. We will crack the case very soon," said Abraham.
The email also mentioned that powerful bombs would go off in four cities including Kochi.